Two new species of trypanosomes (subgenus Schizotrypanum) in bats from southern Ontario

Abstract

From November of 1976 to May of 1979, the blood of 529 bats from 12 sites in southern Ontario was examined for trypanosomes using the haematocrit centrifugation technique. Trypanosoma hedricki n.sp. was found in 62 of 216 Eptesicus fuscus and Trypanosoma myoti n.sp. in 16 of 313 Myotis lucifugus. Blood forms of both species were morphologically similar to Trypanosoma cruzi. These trypanosomes were readily cultured in diphasic blood–agar medium.Cultures of T. hedricki n.sp. and T. myoti n.sp. were infective when inoculated orally or injected intraperitoneally into laboratory reared E. fuscus and M. lucifugus respectively. Pseudocysts of amastigotes were found in cardiac muscles of both bat species and in the intestinal smooth muscle of M. lucifugus. Trypanosoma hedricki n.sp. was not infective to M. lucifugus nor was T. myoti n.sp. infective to E. fuscus. Unlike T. cruzi, cultures were not infective to Mus musculus, Peromyscus maniculatus, Microtus pennsylvanicus, Mesocricetus auratus, Rattus norvegicus, and Cavia porcellus.After in vitro incubation in fresh plasma from deer mice, hamsters, laboratory rats, guinea pigs, little brown bats, and Homo sapiens, T. hedricki n.sp. could not be cultured. However, positive cultures were obtained after incubation in fresh plasma from E. fuscus and occasionally in fresh plasma from laboratory mice. Positive cultures were always obtained when the plasma was heat inactivated.